The present invention relates to network implementation and, more specifically, to an implementation of a protocol to multiple switches in a virtual line aggregate group (LAG).
In many data center environments, downstream servers or switches may connect to upstream devices using uplinks, which may consolidate traffic. For example, a server or a switch may be connected to more than one switch in the aggregation layer to provide for network redundancy. Typically, a Spanning Tree Protocol (RSTP, PVRST, or MSTP) may be used to prevent broadcast loops and block redundant uplink paths. This may have the undesirable result of reducing the available bandwidth between the layers by as much as 50%. In addition, the STP may be slow to resolve topology changes that occur during a link failure or failover scenario. The STP may not for example, be able to resolve differences in switch states among redundant switches. The information transferred from both switches may be inconsistent and thus a failover may result in considerable media access control (MAC) address flooding in a server as both switches attempt to update the server.
Using Virtual Link Aggregation Groups (vLAGs), redundant uplinks may remain active utilizing all available bandwidth. In a vLAG, two switches may be paired as vLAG peers and may act as a single virtual entity for establishing a multi-port trunk. Ports from both peer switches may be grouped into a vLAG and may be connected to the same LAG-capable target device, for example a server. From the perspective of the target device, the ports connected to the vLAG peers appear to be a single trunk connecting to a single logical device.
The 802.1Qbg/Edge Virtual Bridging (EVB) protocol is a standard designed to enable networks to be aware of the presence of virtual machines (VM). This protocol automates the exchange of information between virtual Ethernet bridges. The physical end stations which may contain the VMs may use a bridge to form a local area network (LAN). The virtual network interface card (vNIC) configuration information of a particular VM may typically be made available to the EVB enabled devices.
Conventionally, the 802.1qbg protocol may only be supported for a single uplink switch. The 802.1qbg protocol may be used to provide quality of service (QoS) and access control list (ACL) policies to communicate with VMs in a server which is connected to an adjacent bridge (switch). The 802.1qbg protocol may operate sufficiently in a connection between a server and a single uplink switch. However if the server connects to multiple uplink switches using a LAG and the uplink switches are in a vLAG configuration, the 802.1qbg protocol may not work since there is no mechanism available to synchronize the VM with association/dissociation related information among the vLAG switches.